Compound Growth and Monthly Savings Calculator
Calculate compound growth with an initial balance, monthly savings and an assumed annual return. Compare contribution timing and separate deposits from growth.
Enter the figures you want to check
Calculations run only in your browser. Values are neither saved nor sent to us.
Calculation results
Ending scenario balance
SAR
Total money contributed
SAR
Growth under the assumption
SAR
How are the results calculated?
Monthly rate = nominal annual return ÷ 12.
End-of-month contribution: new balance = previous balance × (1 + monthly rate) + contribution.
Start-of-month contribution: new balance = (previous balance + contribution) × (1 + monthly rate).
Growth = ending balance − starting balance − total contributions.
Assumptions and limits
- This uses a constant illustrative return and is unrelated to any financial product or promised return. Fees, taxes, inflation and price volatility are outside the model.
- The nominal rate is divided by 12 and the balance is rounded to a halala each month. This can differ from an effective annual rate or a provider’s calculation method.
Official source: Investor.gov — Compound interest calculator
Understand the idea behind the calculation
Using the tool and understanding your results
Explore how regular savings and compounding change a balance. Enter an initial amount, monthly contribution, assumed annual return and duration in months, then choose contribution timing. See the ending balance, total money contributed and compound growth separately.
How do I calculate compound interest with monthly savings?
The calculator divides the nominal annual rate by 12 and compounds monthly. For end-of-month deposits, the balance grows before the contribution is added. SAR 1,000 plus SAR 100 monthly at an assumed 12% nominal annual rate gives SAR 1,221.10 after two months, with monthly halala rounding.
What changes when I deposit at the start of the month?
A beginning-of-month contribution joins the balance before that month’s growth is calculated. An end-of-month contribution is added afterward. Choose the timing that matches the scenario you want to review.
Is the ending balance all investment profit?
The ending balance includes your initial amount, deposits and growth. If you contributed SAR 1,200 and the ending balance is SAR 1,221.10, calculated growth is SAR 21.10. The scenario assumes a constant chosen rate and excludes fees, taxes, inflation and changing returns.